Navy looks to Communications & Power to repair and rebuild klystron tubes for shipboard radar

CRANE, Ind., 8 May 2013. U.S. Navy radar experts needed repairs and rebuilds for klystron traveling wave tubes for long-range radar systems on Navy surface warships. They found their solution from Communications & Power Industries LLC in Palo Alto, Calif.

Communications & Power won a $6.9 million contract Monday for evaluations, minor and major repairs, and rebuilds of the klystron traveling wave tubes on the Raytheon AN/SPS-49 two-dimensional, long range air search radar on surface warships such as Perry-class frigates and Ticonderoga-class cruisers.

The klystron traveling wave tube is part of the AN/SPS-49 air search radar that detects and tracks airborne objects within range of the shipboard radar, Navy officials say. These devices also are part of electronic warfare systems.

A klystron is a specialized linear-beam vacuum tube that functions as an amplifier for high frequencies, from UHF radio frequencies up into the microwave range. Low-power klystrons are used as local oscillators in superheterodyne radar receivers.

Klystron amplifiers, as opposed to magnetron amplifier coherently amplifies a reference signal so its output may be controlled precisely in amplitude, frequency, and phase.

Klystrons amplify RF signals by converting the kinetic energy in a DC electron beam into RF power. A thermionic cathode produces a beam of electrons. The beam accelerates by high-voltage electrodes and passes through an input cavity resonator. RF energy feeds into the input cavity at its resonant frequency to produce a voltage that acts on the electron beam.

Klystrons can produce far higher microwave power outputs than solid state microwave devices. They are used in radar, satellite, and wideband high-power communications, medicine, and high-energy particle physics.

The AN/SPS-49 operates in the 851-to-942 MHz, or L- band, and has a range of 256 nautical miles. Its antenna rotates at six revolutions per minute in long range mode or 12 rotations per minute in short-range mode to defend against incoming missiles. The output stage of the transmitter uses a two-cavity klystron amplifier.

Communications & Power will do the work in Palo Alto, Calif., and should be finished by May 2018. Awarding the contract were officials of the Naval Surface Warfare Center in Crane, Ind.